1. Field of the Invention
This invention relates generally to filtration systems, and more particularly to a filtration system for filtering pollutants from vented gasses from a natural gas compressor station.
2. Description of Related Art
Natural gas distribution pipelines include compressor stations to re-compress the natural gas. These compressor stations must periodically be shut down, depressurized, and opened for maintenance and inspection. The gasses that are in the compressor station must be vented as part of this operation. A well known problem with venting the gasses is the pollution caused by venting the hydrocarbons, and associated chemicals (e.g., benzene, etc.).
There are many patents in the prior art that teach various methods of handling vented gasses in the field of hydrocarbon distribution.
Wynn, U.S. Pat. No. 7,350,581, teaches a vapor recovery apparatus for oil and gas well production that is used in combination with a liquid separator, a sales line, a holding tank, and a compressor linked to an engine. A first conduit extends from fluid communication with the holding tank to a compressor inlet, while a second conduit extends from a compressor outlet to fluid communication with the sales line. The vapor recovery apparatus also has an electronic controller that is connected to the engine and to a pressure sensor, which is in fluid communication with the gas in the tank. When the pressure reaches a certain level, the gas is captured and compressed by the compressor, and directed to the holding tank for future use.
Webb, U.S. Pat. No. 5,195,587, teaches in an oilfield production system in which a water driven jet pump is used to evacuate vapors from storage tanks to thereby recover the vapors and prevent emissions from passing to the atmosphere. The jet pump entrains the vapors in process water which is passed to a process separator already in the system. The gas is separated for recovery.
Heath et al., U.S. 2007/0186770, teaches a natural gas well vapor recovery processing system and method that is adapted for recovering gaseous hydrocarbons to prevent their release into the atmosphere. The natural gas is collected and compressed using a compressor for later collection and use.
Mok et al., U.S. 2010/0095845, teaches a vent gas adsorption system and a method of recovering volatile organic compounds (VOCs), more particularly to a vent gas adsorption system devised to effectively adsorb VOCs included in the vent gas and reduce VOC content of the vent gas, and a method of recovering VOCs.
Various forms of filters are, of course, well known. Meyers, U.S. Pat. No. 6,684,945, for example, teaches an air filter for a well is installed within a well casing of the well. The air filter forming an airtight seal around the well casing of the well, such that all the air that enters and exits the well must pass through the air filter. The air filter preferably includes a filter housing, at least one removable gasket and a removable filter cartridge installed within an opening extending through the filter housing. The air filter prevents dirt, dust, bacteria, gaseous chemicals, volatile organic compounds, (VOCs), insects and other air born contaminants from entering and possibly contaminating the well. An air filter may also be installed within a vent pipe extending through a well seal attached to the top of a well casing of a well.
The above-described references are hereby incorporated by reference in full.
The prior art teaches various methods for handling vented gasses to prevent undue pollution. However, the prior art does not teach a filtration system that is adapted to be operably engaged with a compressor station to direct vented gasses through a filter unit before venting these gasses to the atmosphere. The present invention fulfills these needs and provides further related advantages as described in the following summary.